1pub mod parser;
2
3use crate::parser::CodeBlockKind;
4use futures::FutureExt;
5use gpui::{
6 actions, point, quad, AnyElement, App, Bounds, ClipboardItem, CursorStyle, DispatchPhase,
7 Edges, Entity, FocusHandle, Focusable, FontStyle, FontWeight, GlobalElementId, Hitbox, Hsla,
8 KeyContext, Length, MouseDownEvent, MouseEvent, MouseMoveEvent, MouseUpEvent, Point, Render,
9 Stateful, StrikethroughStyle, StyleRefinement, StyledText, Task, TextLayout, TextRun,
10 TextStyle, TextStyleRefinement,
11};
12use language::{Language, LanguageRegistry, Rope};
13use parser::{parse_links_only, parse_markdown, MarkdownEvent, MarkdownTag, MarkdownTagEnd};
14
15use std::{iter, mem, ops::Range, rc::Rc, sync::Arc};
16use theme::SyntaxTheme;
17use ui::{prelude::*, Tooltip};
18use util::{ResultExt, TryFutureExt};
19
20#[derive(Clone)]
21pub struct MarkdownStyle {
22 pub base_text_style: TextStyle,
23 pub code_block: StyleRefinement,
24 pub inline_code: TextStyleRefinement,
25 pub block_quote: TextStyleRefinement,
26 pub link: TextStyleRefinement,
27 pub rule_color: Hsla,
28 pub block_quote_border_color: Hsla,
29 pub syntax: Arc<SyntaxTheme>,
30 pub selection_background_color: Hsla,
31 pub break_style: StyleRefinement,
32 pub heading: StyleRefinement,
33}
34
35impl Default for MarkdownStyle {
36 fn default() -> Self {
37 Self {
38 base_text_style: Default::default(),
39 code_block: Default::default(),
40 inline_code: Default::default(),
41 block_quote: Default::default(),
42 link: Default::default(),
43 rule_color: Default::default(),
44 block_quote_border_color: Default::default(),
45 syntax: Arc::new(SyntaxTheme::default()),
46 selection_background_color: Default::default(),
47 break_style: Default::default(),
48 heading: Default::default(),
49 }
50 }
51}
52pub struct Markdown {
53 source: String,
54 selection: Selection,
55 pressed_link: Option<RenderedLink>,
56 autoscroll_request: Option<usize>,
57 style: MarkdownStyle,
58 parsed_markdown: ParsedMarkdown,
59 should_reparse: bool,
60 pending_parse: Option<Task<Option<()>>>,
61 focus_handle: FocusHandle,
62 language_registry: Option<Arc<LanguageRegistry>>,
63 fallback_code_block_language: Option<String>,
64 options: Options,
65}
66
67#[derive(Debug)]
68struct Options {
69 parse_links_only: bool,
70 copy_code_block_buttons: bool,
71}
72
73actions!(markdown, [Copy]);
74
75impl Markdown {
76 pub fn new(
77 source: String,
78 style: MarkdownStyle,
79 language_registry: Option<Arc<LanguageRegistry>>,
80 fallback_code_block_language: Option<String>,
81 window: &mut Window,
82 cx: &mut Context<Self>,
83 ) -> Self {
84 let focus_handle = cx.focus_handle();
85 let mut this = Self {
86 source,
87 selection: Selection::default(),
88 pressed_link: None,
89 autoscroll_request: None,
90 style,
91 should_reparse: false,
92 parsed_markdown: ParsedMarkdown::default(),
93 pending_parse: None,
94 focus_handle,
95 language_registry,
96 fallback_code_block_language,
97 options: Options {
98 parse_links_only: false,
99 copy_code_block_buttons: true,
100 },
101 };
102 this.parse(window, cx);
103 this
104 }
105
106 pub fn new_text(
107 source: String,
108 style: MarkdownStyle,
109 language_registry: Option<Arc<LanguageRegistry>>,
110 fallback_code_block_language: Option<String>,
111 window: &mut Window,
112 cx: &mut Context<Self>,
113 ) -> Self {
114 let focus_handle = cx.focus_handle();
115 let mut this = Self {
116 source,
117 selection: Selection::default(),
118 pressed_link: None,
119 autoscroll_request: None,
120 style,
121 should_reparse: false,
122 parsed_markdown: ParsedMarkdown::default(),
123 pending_parse: None,
124 focus_handle,
125 language_registry,
126 fallback_code_block_language,
127 options: Options {
128 parse_links_only: true,
129 copy_code_block_buttons: true,
130 },
131 };
132 this.parse(window, cx);
133 this
134 }
135
136 pub fn source(&self) -> &str {
137 &self.source
138 }
139
140 pub fn append(&mut self, text: &str, window: &mut Window, cx: &mut Context<Self>) {
141 self.source.push_str(text);
142 self.parse(window, cx);
143 }
144
145 pub fn reset(&mut self, source: String, window: &mut Window, cx: &mut Context<Self>) {
146 if source == self.source() {
147 return;
148 }
149 self.source = source;
150 self.selection = Selection::default();
151 self.autoscroll_request = None;
152 self.pending_parse = None;
153 self.should_reparse = false;
154 self.parsed_markdown = ParsedMarkdown::default();
155 self.parse(window, cx);
156 }
157
158 pub fn parsed_markdown(&self) -> &ParsedMarkdown {
159 &self.parsed_markdown
160 }
161
162 fn copy(&self, text: &RenderedText, _: &mut Window, cx: &mut Context<Self>) {
163 if self.selection.end <= self.selection.start {
164 return;
165 }
166 let text = text.text_for_range(self.selection.start..self.selection.end);
167 cx.write_to_clipboard(ClipboardItem::new_string(text));
168 }
169
170 fn parse(&mut self, window: &mut Window, cx: &mut Context<Self>) {
171 if self.source.is_empty() {
172 return;
173 }
174
175 if self.pending_parse.is_some() {
176 self.should_reparse = true;
177 return;
178 }
179
180 let text = self.source.clone();
181 let parse_text_only = self.options.parse_links_only;
182 let parsed = cx.background_executor().spawn(async move {
183 let text = SharedString::from(text);
184 let events = match parse_text_only {
185 true => Arc::from(parse_links_only(text.as_ref())),
186 false => Arc::from(parse_markdown(text.as_ref())),
187 };
188 anyhow::Ok(ParsedMarkdown {
189 source: text,
190 events,
191 })
192 });
193
194 self.should_reparse = false;
195 self.pending_parse = Some(cx.spawn_in(window, |this, mut cx| {
196 async move {
197 let parsed = parsed.await?;
198 this.update_in(&mut cx, |this, window, cx| {
199 this.parsed_markdown = parsed;
200 this.pending_parse.take();
201 if this.should_reparse {
202 this.parse(window, cx);
203 }
204 cx.notify();
205 })
206 .ok();
207 anyhow::Ok(())
208 }
209 .log_err()
210 }));
211 }
212
213 pub fn copy_code_block_buttons(mut self, should_copy: bool) -> Self {
214 self.options.copy_code_block_buttons = should_copy;
215 self
216 }
217}
218
219impl Render for Markdown {
220 fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
221 MarkdownElement::new(
222 cx.entity().clone(),
223 self.style.clone(),
224 self.language_registry.clone(),
225 self.fallback_code_block_language.clone(),
226 )
227 }
228}
229
230impl Focusable for Markdown {
231 fn focus_handle(&self, _cx: &App) -> FocusHandle {
232 self.focus_handle.clone()
233 }
234}
235
236#[derive(Copy, Clone, Default, Debug)]
237struct Selection {
238 start: usize,
239 end: usize,
240 reversed: bool,
241 pending: bool,
242}
243
244impl Selection {
245 fn set_head(&mut self, head: usize) {
246 if head < self.tail() {
247 if !self.reversed {
248 self.end = self.start;
249 self.reversed = true;
250 }
251 self.start = head;
252 } else {
253 if self.reversed {
254 self.start = self.end;
255 self.reversed = false;
256 }
257 self.end = head;
258 }
259 }
260
261 fn tail(&self) -> usize {
262 if self.reversed {
263 self.end
264 } else {
265 self.start
266 }
267 }
268}
269
270#[derive(Clone, Default)]
271pub struct ParsedMarkdown {
272 source: SharedString,
273 events: Arc<[(Range<usize>, MarkdownEvent)]>,
274}
275
276impl ParsedMarkdown {
277 pub fn source(&self) -> &SharedString {
278 &self.source
279 }
280
281 pub fn events(&self) -> &Arc<[(Range<usize>, MarkdownEvent)]> {
282 &self.events
283 }
284}
285
286pub struct MarkdownElement {
287 markdown: Entity<Markdown>,
288 style: MarkdownStyle,
289 language_registry: Option<Arc<LanguageRegistry>>,
290 fallback_code_block_language: Option<String>,
291}
292
293impl MarkdownElement {
294 fn new(
295 markdown: Entity<Markdown>,
296 style: MarkdownStyle,
297 language_registry: Option<Arc<LanguageRegistry>>,
298 fallback_code_block_language: Option<String>,
299 ) -> Self {
300 Self {
301 markdown,
302 style,
303 language_registry,
304 fallback_code_block_language,
305 }
306 }
307
308 fn load_language(
309 &self,
310 name: &str,
311 window: &mut Window,
312 cx: &mut App,
313 ) -> Option<Arc<Language>> {
314 let language_test = self.language_registry.as_ref()?.language_for_name(name);
315
316 let language_name = match language_test.now_or_never() {
317 Some(Ok(_)) => String::from(name),
318 Some(Err(_)) if !name.is_empty() && self.fallback_code_block_language.is_some() => {
319 self.fallback_code_block_language.clone().unwrap()
320 }
321 _ => String::new(),
322 };
323
324 let language = self
325 .language_registry
326 .as_ref()?
327 .language_for_name(language_name.as_str())
328 .map(|language| language.ok())
329 .shared();
330
331 match language.clone().now_or_never() {
332 Some(language) => language,
333 None => {
334 let markdown = self.markdown.downgrade();
335 window
336 .spawn(cx, |mut cx| async move {
337 language.await;
338 markdown.update(&mut cx, |_, cx| cx.notify())
339 })
340 .detach_and_log_err(cx);
341 None
342 }
343 }
344 }
345
346 fn paint_selection(
347 &self,
348 bounds: Bounds<Pixels>,
349 rendered_text: &RenderedText,
350 window: &mut Window,
351 cx: &mut App,
352 ) {
353 let selection = self.markdown.read(cx).selection;
354 let selection_start = rendered_text.position_for_source_index(selection.start);
355 let selection_end = rendered_text.position_for_source_index(selection.end);
356
357 if let Some(((start_position, start_line_height), (end_position, end_line_height))) =
358 selection_start.zip(selection_end)
359 {
360 if start_position.y == end_position.y {
361 window.paint_quad(quad(
362 Bounds::from_corners(
363 start_position,
364 point(end_position.x, end_position.y + end_line_height),
365 ),
366 Pixels::ZERO,
367 self.style.selection_background_color,
368 Edges::default(),
369 Hsla::transparent_black(),
370 ));
371 } else {
372 window.paint_quad(quad(
373 Bounds::from_corners(
374 start_position,
375 point(bounds.right(), start_position.y + start_line_height),
376 ),
377 Pixels::ZERO,
378 self.style.selection_background_color,
379 Edges::default(),
380 Hsla::transparent_black(),
381 ));
382
383 if end_position.y > start_position.y + start_line_height {
384 window.paint_quad(quad(
385 Bounds::from_corners(
386 point(bounds.left(), start_position.y + start_line_height),
387 point(bounds.right(), end_position.y),
388 ),
389 Pixels::ZERO,
390 self.style.selection_background_color,
391 Edges::default(),
392 Hsla::transparent_black(),
393 ));
394 }
395
396 window.paint_quad(quad(
397 Bounds::from_corners(
398 point(bounds.left(), end_position.y),
399 point(end_position.x, end_position.y + end_line_height),
400 ),
401 Pixels::ZERO,
402 self.style.selection_background_color,
403 Edges::default(),
404 Hsla::transparent_black(),
405 ));
406 }
407 }
408 }
409
410 fn paint_mouse_listeners(
411 &self,
412 hitbox: &Hitbox,
413 rendered_text: &RenderedText,
414 window: &mut Window,
415 cx: &mut App,
416 ) {
417 let is_hovering_link = hitbox.is_hovered(window)
418 && !self.markdown.read(cx).selection.pending
419 && rendered_text
420 .link_for_position(window.mouse_position())
421 .is_some();
422
423 if is_hovering_link {
424 window.set_cursor_style(CursorStyle::PointingHand, hitbox);
425 } else {
426 window.set_cursor_style(CursorStyle::IBeam, hitbox);
427 }
428
429 self.on_mouse_event(window, cx, {
430 let rendered_text = rendered_text.clone();
431 let hitbox = hitbox.clone();
432 move |markdown, event: &MouseDownEvent, phase, window, cx| {
433 if hitbox.is_hovered(window) {
434 if phase.bubble() {
435 if let Some(link) = rendered_text.link_for_position(event.position) {
436 markdown.pressed_link = Some(link.clone());
437 } else {
438 let source_index =
439 match rendered_text.source_index_for_position(event.position) {
440 Ok(ix) | Err(ix) => ix,
441 };
442 let range = if event.click_count == 2 {
443 rendered_text.surrounding_word_range(source_index)
444 } else if event.click_count == 3 {
445 rendered_text.surrounding_line_range(source_index)
446 } else {
447 source_index..source_index
448 };
449 markdown.selection = Selection {
450 start: range.start,
451 end: range.end,
452 reversed: false,
453 pending: true,
454 };
455 window.focus(&markdown.focus_handle);
456 window.prevent_default()
457 }
458
459 cx.notify();
460 }
461 } else if phase.capture() {
462 markdown.selection = Selection::default();
463 markdown.pressed_link = None;
464 cx.notify();
465 }
466 }
467 });
468 self.on_mouse_event(window, cx, {
469 let rendered_text = rendered_text.clone();
470 let hitbox = hitbox.clone();
471 let was_hovering_link = is_hovering_link;
472 move |markdown, event: &MouseMoveEvent, phase, window, cx| {
473 if phase.capture() {
474 return;
475 }
476
477 if markdown.selection.pending {
478 let source_index = match rendered_text.source_index_for_position(event.position)
479 {
480 Ok(ix) | Err(ix) => ix,
481 };
482 markdown.selection.set_head(source_index);
483 markdown.autoscroll_request = Some(source_index);
484 cx.notify();
485 } else {
486 let is_hovering_link = hitbox.is_hovered(window)
487 && rendered_text.link_for_position(event.position).is_some();
488 if is_hovering_link != was_hovering_link {
489 cx.notify();
490 }
491 }
492 }
493 });
494 self.on_mouse_event(window, cx, {
495 let rendered_text = rendered_text.clone();
496 move |markdown, event: &MouseUpEvent, phase, _, cx| {
497 if phase.bubble() {
498 if let Some(pressed_link) = markdown.pressed_link.take() {
499 if Some(&pressed_link) == rendered_text.link_for_position(event.position) {
500 cx.open_url(&pressed_link.destination_url);
501 }
502 }
503 } else if markdown.selection.pending {
504 markdown.selection.pending = false;
505 #[cfg(any(target_os = "linux", target_os = "freebsd"))]
506 {
507 let text = rendered_text
508 .text_for_range(markdown.selection.start..markdown.selection.end);
509 cx.write_to_primary(ClipboardItem::new_string(text))
510 }
511 cx.notify();
512 }
513 }
514 });
515 }
516
517 fn autoscroll(
518 &self,
519 rendered_text: &RenderedText,
520 window: &mut Window,
521 cx: &mut App,
522 ) -> Option<()> {
523 let autoscroll_index = self
524 .markdown
525 .update(cx, |markdown, _| markdown.autoscroll_request.take())?;
526 let (position, line_height) = rendered_text.position_for_source_index(autoscroll_index)?;
527
528 let text_style = self.style.base_text_style.clone();
529 let font_id = window.text_system().resolve_font(&text_style.font());
530 let font_size = text_style.font_size.to_pixels(window.rem_size());
531 let em_width = window.text_system().em_width(font_id, font_size).unwrap();
532 window.request_autoscroll(Bounds::from_corners(
533 point(position.x - 3. * em_width, position.y - 3. * line_height),
534 point(position.x + 3. * em_width, position.y + 3. * line_height),
535 ));
536 Some(())
537 }
538
539 fn on_mouse_event<T: MouseEvent>(
540 &self,
541 window: &mut Window,
542 _cx: &mut App,
543 mut f: impl 'static
544 + FnMut(&mut Markdown, &T, DispatchPhase, &mut Window, &mut Context<Markdown>),
545 ) {
546 window.on_mouse_event({
547 let markdown = self.markdown.downgrade();
548 move |event, phase, window, cx| {
549 markdown
550 .update(cx, |markdown, cx| f(markdown, event, phase, window, cx))
551 .log_err();
552 }
553 });
554 }
555}
556
557impl Element for MarkdownElement {
558 type RequestLayoutState = RenderedMarkdown;
559 type PrepaintState = Hitbox;
560
561 fn id(&self) -> Option<ElementId> {
562 None
563 }
564
565 fn request_layout(
566 &mut self,
567 _id: Option<&GlobalElementId>,
568 window: &mut Window,
569 cx: &mut App,
570 ) -> (gpui::LayoutId, Self::RequestLayoutState) {
571 let mut builder = MarkdownElementBuilder::new(
572 self.style.base_text_style.clone(),
573 self.style.syntax.clone(),
574 );
575 let parsed_markdown = self.markdown.read(cx).parsed_markdown.clone();
576 let markdown_end = if let Some(last) = parsed_markdown.events.last() {
577 last.0.end
578 } else {
579 0
580 };
581 for (range, event) in parsed_markdown.events.iter() {
582 match event {
583 MarkdownEvent::Start(tag) => {
584 match tag {
585 MarkdownTag::Paragraph => {
586 builder.push_div(
587 div().mb_2().line_height(rems(1.3)),
588 range,
589 markdown_end,
590 );
591 }
592 MarkdownTag::Heading { level, .. } => {
593 let mut heading = div().mb_2();
594 heading = match level {
595 pulldown_cmark::HeadingLevel::H1 => heading.text_3xl(),
596 pulldown_cmark::HeadingLevel::H2 => heading.text_2xl(),
597 pulldown_cmark::HeadingLevel::H3 => heading.text_xl(),
598 pulldown_cmark::HeadingLevel::H4 => heading.text_lg(),
599 _ => heading,
600 };
601 heading.style().refine(&self.style.heading);
602 builder.push_text_style(
603 self.style.heading.text_style().clone().unwrap_or_default(),
604 );
605 builder.push_div(heading, range, markdown_end);
606 }
607 MarkdownTag::BlockQuote => {
608 builder.push_text_style(self.style.block_quote.clone());
609 builder.push_div(
610 div()
611 .pl_4()
612 .mb_2()
613 .border_l_4()
614 .border_color(self.style.block_quote_border_color),
615 range,
616 markdown_end,
617 );
618 }
619 MarkdownTag::CodeBlock(kind) => {
620 let language = if let CodeBlockKind::Fenced(language) = kind {
621 self.load_language(language.as_ref(), window, cx)
622 } else {
623 None
624 };
625
626 let mut d = div().w_full().rounded_lg();
627 d.style().refine(&self.style.code_block);
628 if let Some(code_block_text_style) = &self.style.code_block.text {
629 builder.push_text_style(code_block_text_style.to_owned());
630 }
631 builder.push_code_block(language);
632 builder.push_div(d, range, markdown_end);
633 }
634 MarkdownTag::HtmlBlock => builder.push_div(div(), range, markdown_end),
635 MarkdownTag::List(bullet_index) => {
636 builder.push_list(*bullet_index);
637 builder.push_div(div().pl_4(), range, markdown_end);
638 }
639 MarkdownTag::Item => {
640 let bullet = if let Some(bullet_index) = builder.next_bullet_index() {
641 format!("{}.", bullet_index)
642 } else {
643 "•".to_string()
644 };
645 builder.push_div(
646 div()
647 .mb_1()
648 .h_flex()
649 .items_start()
650 .gap_1()
651 .line_height(rems(1.3))
652 .child(bullet),
653 range,
654 markdown_end,
655 );
656 // Without `w_0`, text doesn't wrap to the width of the container.
657 builder.push_div(div().flex_1().w_0(), range, markdown_end);
658 }
659 MarkdownTag::Emphasis => builder.push_text_style(TextStyleRefinement {
660 font_style: Some(FontStyle::Italic),
661 ..Default::default()
662 }),
663 MarkdownTag::Strong => builder.push_text_style(TextStyleRefinement {
664 font_weight: Some(FontWeight::BOLD),
665 ..Default::default()
666 }),
667 MarkdownTag::Strikethrough => {
668 builder.push_text_style(TextStyleRefinement {
669 strikethrough: Some(StrikethroughStyle {
670 thickness: px(1.),
671 color: None,
672 }),
673 ..Default::default()
674 })
675 }
676 MarkdownTag::Link { dest_url, .. } => {
677 if builder.code_block_stack.is_empty() {
678 builder.push_link(dest_url.clone(), range.clone());
679 builder.push_text_style(self.style.link.clone())
680 }
681 }
682 MarkdownTag::MetadataBlock(_) => {}
683 _ => log::error!("unsupported markdown tag {:?}", tag),
684 }
685 }
686 MarkdownEvent::End(tag) => match tag {
687 MarkdownTagEnd::Paragraph => {
688 builder.pop_div();
689 }
690 MarkdownTagEnd::Heading(_) => {
691 builder.pop_div();
692 builder.pop_text_style()
693 }
694 MarkdownTagEnd::BlockQuote(_kind) => {
695 builder.pop_text_style();
696 builder.pop_div()
697 }
698 MarkdownTagEnd::CodeBlock => {
699 builder.trim_trailing_newline();
700
701 if self.markdown.read(cx).options.copy_code_block_buttons {
702 builder.flush_text();
703 builder.modify_current_div(|el| {
704 let id =
705 ElementId::NamedInteger("copy-markdown-code".into(), range.end);
706 let copy_button = div().absolute().top_1().right_1().w_5().child(
707 IconButton::new(id, IconName::Copy)
708 .icon_color(Color::Muted)
709 .shape(ui::IconButtonShape::Square)
710 .tooltip(Tooltip::text("Copy Code Block"))
711 .on_click({
712 let code = without_fences(
713 parsed_markdown.source()[range.clone()].trim(),
714 )
715 .to_string();
716
717 move |_, _, cx| {
718 cx.write_to_clipboard(ClipboardItem::new_string(
719 code.clone(),
720 ))
721 }
722 }),
723 );
724
725 el.child(copy_button)
726 });
727 }
728
729 builder.pop_div();
730 builder.pop_code_block();
731 if self.style.code_block.text.is_some() {
732 builder.pop_text_style();
733 }
734 }
735 MarkdownTagEnd::HtmlBlock => builder.pop_div(),
736 MarkdownTagEnd::List(_) => {
737 builder.pop_list();
738 builder.pop_div();
739 }
740 MarkdownTagEnd::Item => {
741 builder.pop_div();
742 builder.pop_div();
743 }
744 MarkdownTagEnd::Emphasis => builder.pop_text_style(),
745 MarkdownTagEnd::Strong => builder.pop_text_style(),
746 MarkdownTagEnd::Strikethrough => builder.pop_text_style(),
747 MarkdownTagEnd::Link => {
748 if builder.code_block_stack.is_empty() {
749 builder.pop_text_style()
750 }
751 }
752 _ => log::error!("unsupported markdown tag end: {:?}", tag),
753 },
754 MarkdownEvent::Text => {
755 builder.push_text(&parsed_markdown.source[range.clone()], range.start);
756 }
757 MarkdownEvent::Code => {
758 builder.push_text_style(self.style.inline_code.clone());
759 builder.push_text(&parsed_markdown.source[range.clone()], range.start);
760 builder.pop_text_style();
761 }
762 MarkdownEvent::Html => {
763 builder.push_text(&parsed_markdown.source[range.clone()], range.start);
764 }
765 MarkdownEvent::InlineHtml => {
766 builder.push_text(&parsed_markdown.source[range.clone()], range.start);
767 }
768 MarkdownEvent::Rule => {
769 builder.push_div(
770 div()
771 .border_b_1()
772 .my_2()
773 .border_color(self.style.rule_color),
774 range,
775 markdown_end,
776 );
777 builder.pop_div()
778 }
779 MarkdownEvent::SoftBreak => builder.push_text(" ", range.start),
780 MarkdownEvent::HardBreak => {
781 let mut d = div().py_3();
782 d.style().refine(&self.style.break_style);
783 builder.push_div(d, range, markdown_end);
784 builder.pop_div()
785 }
786 _ => log::error!("unsupported markdown event {:?}", event),
787 }
788 }
789 let mut rendered_markdown = builder.build();
790 let child_layout_id = rendered_markdown.element.request_layout(window, cx);
791 let layout_id = window.request_layout(gpui::Style::default(), [child_layout_id], cx);
792 (layout_id, rendered_markdown)
793 }
794
795 fn prepaint(
796 &mut self,
797 _id: Option<&GlobalElementId>,
798 bounds: Bounds<Pixels>,
799 rendered_markdown: &mut Self::RequestLayoutState,
800 window: &mut Window,
801 cx: &mut App,
802 ) -> Self::PrepaintState {
803 let focus_handle = self.markdown.read(cx).focus_handle.clone();
804 window.set_focus_handle(&focus_handle, cx);
805
806 let hitbox = window.insert_hitbox(bounds, false);
807 rendered_markdown.element.prepaint(window, cx);
808 self.autoscroll(&rendered_markdown.text, window, cx);
809 hitbox
810 }
811
812 fn paint(
813 &mut self,
814 _id: Option<&GlobalElementId>,
815 bounds: Bounds<Pixels>,
816 rendered_markdown: &mut Self::RequestLayoutState,
817 hitbox: &mut Self::PrepaintState,
818 window: &mut Window,
819 cx: &mut App,
820 ) {
821 let mut context = KeyContext::default();
822 context.add("Markdown");
823 window.set_key_context(context);
824 let model = self.markdown.clone();
825 window.on_action(std::any::TypeId::of::<crate::Copy>(), {
826 let text = rendered_markdown.text.clone();
827 move |_, phase, window, cx| {
828 let text = text.clone();
829 if phase == DispatchPhase::Bubble {
830 model.update(cx, move |this, cx| this.copy(&text, window, cx))
831 }
832 }
833 });
834
835 self.paint_mouse_listeners(hitbox, &rendered_markdown.text, window, cx);
836 rendered_markdown.element.paint(window, cx);
837 self.paint_selection(bounds, &rendered_markdown.text, window, cx);
838 }
839}
840
841impl IntoElement for MarkdownElement {
842 type Element = Self;
843
844 fn into_element(self) -> Self::Element {
845 self
846 }
847}
848
849enum AnyDiv {
850 Div(Div),
851 Stateful(Stateful<Div>),
852}
853
854impl AnyDiv {
855 fn into_any_element(self) -> AnyElement {
856 match self {
857 Self::Div(div) => div.into_any_element(),
858 Self::Stateful(div) => div.into_any_element(),
859 }
860 }
861}
862
863impl From<Div> for AnyDiv {
864 fn from(value: Div) -> Self {
865 Self::Div(value)
866 }
867}
868
869impl From<Stateful<Div>> for AnyDiv {
870 fn from(value: Stateful<Div>) -> Self {
871 Self::Stateful(value)
872 }
873}
874
875impl Styled for AnyDiv {
876 fn style(&mut self) -> &mut StyleRefinement {
877 match self {
878 Self::Div(div) => div.style(),
879 Self::Stateful(div) => div.style(),
880 }
881 }
882}
883
884impl ParentElement for AnyDiv {
885 fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
886 match self {
887 Self::Div(div) => div.extend(elements),
888 Self::Stateful(div) => div.extend(elements),
889 }
890 }
891}
892
893struct MarkdownElementBuilder {
894 div_stack: Vec<AnyDiv>,
895 rendered_lines: Vec<RenderedLine>,
896 pending_line: PendingLine,
897 rendered_links: Vec<RenderedLink>,
898 current_source_index: usize,
899 base_text_style: TextStyle,
900 text_style_stack: Vec<TextStyleRefinement>,
901 code_block_stack: Vec<Option<Arc<Language>>>,
902 list_stack: Vec<ListStackEntry>,
903 syntax_theme: Arc<SyntaxTheme>,
904}
905
906#[derive(Default)]
907struct PendingLine {
908 text: String,
909 runs: Vec<TextRun>,
910 source_mappings: Vec<SourceMapping>,
911}
912
913struct ListStackEntry {
914 bullet_index: Option<u64>,
915}
916
917impl MarkdownElementBuilder {
918 fn new(base_text_style: TextStyle, syntax_theme: Arc<SyntaxTheme>) -> Self {
919 Self {
920 div_stack: vec![div().debug_selector(|| "inner".into()).into()],
921 rendered_lines: Vec::new(),
922 pending_line: PendingLine::default(),
923 rendered_links: Vec::new(),
924 current_source_index: 0,
925 base_text_style,
926 text_style_stack: Vec::new(),
927 code_block_stack: Vec::new(),
928 list_stack: Vec::new(),
929 syntax_theme,
930 }
931 }
932
933 fn push_text_style(&mut self, style: TextStyleRefinement) {
934 self.text_style_stack.push(style);
935 }
936
937 fn text_style(&self) -> TextStyle {
938 let mut style = self.base_text_style.clone();
939 for refinement in &self.text_style_stack {
940 style.refine(refinement);
941 }
942 style
943 }
944
945 fn pop_text_style(&mut self) {
946 self.text_style_stack.pop();
947 }
948
949 fn push_div(&mut self, div: impl Into<AnyDiv>, range: &Range<usize>, markdown_end: usize) {
950 let mut div = div.into();
951 self.flush_text();
952
953 if range.start == 0 {
954 // Remove the top margin on the first element.
955 div.style().refine(&StyleRefinement {
956 margin: gpui::EdgesRefinement {
957 top: Some(Length::Definite(px(0.).into())),
958 left: None,
959 right: None,
960 bottom: None,
961 },
962 ..Default::default()
963 });
964 }
965
966 if range.end == markdown_end {
967 div.style().refine(&StyleRefinement {
968 margin: gpui::EdgesRefinement {
969 top: None,
970 left: None,
971 right: None,
972 bottom: Some(Length::Definite(rems(0.).into())),
973 },
974 ..Default::default()
975 });
976 }
977
978 self.div_stack.push(div);
979 }
980
981 fn modify_current_div(&mut self, f: impl FnOnce(AnyDiv) -> AnyDiv) {
982 self.flush_text();
983 if let Some(div) = self.div_stack.pop() {
984 self.div_stack.push(f(div));
985 }
986 }
987
988 fn pop_div(&mut self) {
989 self.flush_text();
990 let div = self.div_stack.pop().unwrap().into_any_element();
991 self.div_stack.last_mut().unwrap().extend(iter::once(div));
992 }
993
994 fn push_list(&mut self, bullet_index: Option<u64>) {
995 self.list_stack.push(ListStackEntry { bullet_index });
996 }
997
998 fn next_bullet_index(&mut self) -> Option<u64> {
999 self.list_stack.last_mut().and_then(|entry| {
1000 let item_index = entry.bullet_index.as_mut()?;
1001 *item_index += 1;
1002 Some(*item_index - 1)
1003 })
1004 }
1005
1006 fn pop_list(&mut self) {
1007 self.list_stack.pop();
1008 }
1009
1010 fn push_code_block(&mut self, language: Option<Arc<Language>>) {
1011 self.code_block_stack.push(language);
1012 }
1013
1014 fn pop_code_block(&mut self) {
1015 self.code_block_stack.pop();
1016 }
1017
1018 fn push_link(&mut self, destination_url: SharedString, source_range: Range<usize>) {
1019 self.rendered_links.push(RenderedLink {
1020 source_range,
1021 destination_url,
1022 });
1023 }
1024
1025 fn push_text(&mut self, text: &str, source_index: usize) {
1026 self.pending_line.source_mappings.push(SourceMapping {
1027 rendered_index: self.pending_line.text.len(),
1028 source_index,
1029 });
1030 self.pending_line.text.push_str(text);
1031 self.current_source_index = source_index + text.len();
1032
1033 if let Some(Some(language)) = self.code_block_stack.last() {
1034 let mut offset = 0;
1035 for (range, highlight_id) in language.highlight_text(&Rope::from(text), 0..text.len()) {
1036 if range.start > offset {
1037 self.pending_line
1038 .runs
1039 .push(self.text_style().to_run(range.start - offset));
1040 }
1041
1042 let mut run_style = self.text_style();
1043 if let Some(highlight) = highlight_id.style(&self.syntax_theme) {
1044 run_style = run_style.highlight(highlight);
1045 }
1046 self.pending_line.runs.push(run_style.to_run(range.len()));
1047 offset = range.end;
1048 }
1049
1050 if offset < text.len() {
1051 self.pending_line
1052 .runs
1053 .push(self.text_style().to_run(text.len() - offset));
1054 }
1055 } else {
1056 self.pending_line
1057 .runs
1058 .push(self.text_style().to_run(text.len()));
1059 }
1060 }
1061
1062 fn trim_trailing_newline(&mut self) {
1063 if self.pending_line.text.ends_with('\n') {
1064 self.pending_line
1065 .text
1066 .truncate(self.pending_line.text.len() - 1);
1067 self.pending_line.runs.last_mut().unwrap().len -= 1;
1068 self.current_source_index -= 1;
1069 }
1070 }
1071
1072 fn flush_text(&mut self) {
1073 let line = mem::take(&mut self.pending_line);
1074 if line.text.is_empty() {
1075 return;
1076 }
1077
1078 let text = StyledText::new(line.text).with_runs(line.runs);
1079 self.rendered_lines.push(RenderedLine {
1080 layout: text.layout().clone(),
1081 source_mappings: line.source_mappings,
1082 source_end: self.current_source_index,
1083 });
1084 self.div_stack.last_mut().unwrap().extend([text.into_any()]);
1085 }
1086
1087 fn build(mut self) -> RenderedMarkdown {
1088 debug_assert_eq!(self.div_stack.len(), 1);
1089 self.flush_text();
1090 RenderedMarkdown {
1091 element: self.div_stack.pop().unwrap().into_any_element(),
1092 text: RenderedText {
1093 lines: self.rendered_lines.into(),
1094 links: self.rendered_links.into(),
1095 },
1096 }
1097 }
1098}
1099
1100struct RenderedLine {
1101 layout: TextLayout,
1102 source_mappings: Vec<SourceMapping>,
1103 source_end: usize,
1104}
1105
1106impl RenderedLine {
1107 fn rendered_index_for_source_index(&self, source_index: usize) -> usize {
1108 let mapping = match self
1109 .source_mappings
1110 .binary_search_by_key(&source_index, |probe| probe.source_index)
1111 {
1112 Ok(ix) => &self.source_mappings[ix],
1113 Err(ix) => &self.source_mappings[ix - 1],
1114 };
1115 mapping.rendered_index + (source_index - mapping.source_index)
1116 }
1117
1118 fn source_index_for_rendered_index(&self, rendered_index: usize) -> usize {
1119 let mapping = match self
1120 .source_mappings
1121 .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
1122 {
1123 Ok(ix) => &self.source_mappings[ix],
1124 Err(ix) => &self.source_mappings[ix - 1],
1125 };
1126 mapping.source_index + (rendered_index - mapping.rendered_index)
1127 }
1128
1129 fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
1130 let line_rendered_index;
1131 let out_of_bounds;
1132 match self.layout.index_for_position(position) {
1133 Ok(ix) => {
1134 line_rendered_index = ix;
1135 out_of_bounds = false;
1136 }
1137 Err(ix) => {
1138 line_rendered_index = ix;
1139 out_of_bounds = true;
1140 }
1141 };
1142 let source_index = self.source_index_for_rendered_index(line_rendered_index);
1143 if out_of_bounds {
1144 Err(source_index)
1145 } else {
1146 Ok(source_index)
1147 }
1148 }
1149}
1150
1151#[derive(Copy, Clone, Debug, Default)]
1152struct SourceMapping {
1153 rendered_index: usize,
1154 source_index: usize,
1155}
1156
1157pub struct RenderedMarkdown {
1158 element: AnyElement,
1159 text: RenderedText,
1160}
1161
1162#[derive(Clone)]
1163struct RenderedText {
1164 lines: Rc<[RenderedLine]>,
1165 links: Rc<[RenderedLink]>,
1166}
1167
1168#[derive(Clone, Eq, PartialEq)]
1169struct RenderedLink {
1170 source_range: Range<usize>,
1171 destination_url: SharedString,
1172}
1173
1174impl RenderedText {
1175 fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
1176 let mut lines = self.lines.iter().peekable();
1177
1178 while let Some(line) = lines.next() {
1179 let line_bounds = line.layout.bounds();
1180 if position.y > line_bounds.bottom() {
1181 if let Some(next_line) = lines.peek() {
1182 if position.y < next_line.layout.bounds().top() {
1183 return Err(line.source_end);
1184 }
1185 }
1186
1187 continue;
1188 }
1189
1190 return line.source_index_for_position(position);
1191 }
1192
1193 Err(self.lines.last().map_or(0, |line| line.source_end))
1194 }
1195
1196 fn position_for_source_index(&self, source_index: usize) -> Option<(Point<Pixels>, Pixels)> {
1197 for line in self.lines.iter() {
1198 let line_source_start = line.source_mappings.first().unwrap().source_index;
1199 if source_index < line_source_start {
1200 break;
1201 } else if source_index > line.source_end {
1202 continue;
1203 } else {
1204 let line_height = line.layout.line_height();
1205 let rendered_index_within_line = line.rendered_index_for_source_index(source_index);
1206 let position = line.layout.position_for_index(rendered_index_within_line)?;
1207 return Some((position, line_height));
1208 }
1209 }
1210 None
1211 }
1212
1213 fn surrounding_word_range(&self, source_index: usize) -> Range<usize> {
1214 for line in self.lines.iter() {
1215 if source_index > line.source_end {
1216 continue;
1217 }
1218
1219 let line_rendered_start = line.source_mappings.first().unwrap().rendered_index;
1220 let rendered_index_in_line =
1221 line.rendered_index_for_source_index(source_index) - line_rendered_start;
1222 let text = line.layout.text();
1223 let previous_space = if let Some(idx) = text[0..rendered_index_in_line].rfind(' ') {
1224 idx + ' '.len_utf8()
1225 } else {
1226 0
1227 };
1228 let next_space = if let Some(idx) = text[rendered_index_in_line..].find(' ') {
1229 rendered_index_in_line + idx
1230 } else {
1231 text.len()
1232 };
1233
1234 return line.source_index_for_rendered_index(line_rendered_start + previous_space)
1235 ..line.source_index_for_rendered_index(line_rendered_start + next_space);
1236 }
1237
1238 source_index..source_index
1239 }
1240
1241 fn surrounding_line_range(&self, source_index: usize) -> Range<usize> {
1242 for line in self.lines.iter() {
1243 if source_index > line.source_end {
1244 continue;
1245 }
1246 let line_source_start = line.source_mappings.first().unwrap().source_index;
1247 return line_source_start..line.source_end;
1248 }
1249
1250 source_index..source_index
1251 }
1252
1253 fn text_for_range(&self, range: Range<usize>) -> String {
1254 let mut ret = vec![];
1255
1256 for line in self.lines.iter() {
1257 if range.start > line.source_end {
1258 continue;
1259 }
1260 let line_source_start = line.source_mappings.first().unwrap().source_index;
1261 if range.end < line_source_start {
1262 break;
1263 }
1264
1265 let text = line.layout.text();
1266
1267 let start = if range.start < line_source_start {
1268 0
1269 } else {
1270 line.rendered_index_for_source_index(range.start)
1271 };
1272 let end = if range.end > line.source_end {
1273 line.rendered_index_for_source_index(line.source_end)
1274 } else {
1275 line.rendered_index_for_source_index(range.end)
1276 }
1277 .min(text.len());
1278
1279 ret.push(text[start..end].to_string());
1280 }
1281 ret.join("\n")
1282 }
1283
1284 fn link_for_position(&self, position: Point<Pixels>) -> Option<&RenderedLink> {
1285 let source_index = self.source_index_for_position(position).ok()?;
1286 self.links
1287 .iter()
1288 .find(|link| link.source_range.contains(&source_index))
1289 }
1290}
1291
1292/// Some markdown blocks are indented, and others have e.g. ```rust … ``` around them.
1293/// If this block is fenced with backticks, strip them off (and the language name).
1294/// We use this when copying code blocks to the clipboard.
1295fn without_fences(mut markdown: &str) -> &str {
1296 if let Some(opening_backticks) = markdown.find("```") {
1297 markdown = &markdown[opening_backticks..];
1298
1299 // Trim off the next newline. This also trims off a language name if it's there.
1300 if let Some(newline) = markdown.find('\n') {
1301 markdown = &markdown[newline + 1..];
1302 }
1303 };
1304
1305 if let Some(closing_backticks) = markdown.rfind("```") {
1306 markdown = &markdown[..closing_backticks];
1307 };
1308
1309 markdown
1310}
1311
1312#[cfg(test)]
1313mod tests {
1314 use super::*;
1315
1316 #[test]
1317 fn test_without_fences() {
1318 let input = "```rust\nlet x = 5;\n```";
1319 assert_eq!(without_fences(input), "let x = 5;\n");
1320
1321 let input = " ```\nno language\n``` ";
1322 assert_eq!(without_fences(input), "no language\n");
1323
1324 let input = "plain text";
1325 assert_eq!(without_fences(input), "plain text");
1326
1327 let input = "```python\nprint('hello')\nprint('world')\n```";
1328 assert_eq!(without_fences(input), "print('hello')\nprint('world')\n");
1329 }
1330}